RNA 5-methylcytosine status is associated with DNMT2/TRDMT1 nuclear localization in osteosarcoma cell lines

Gabriela Betlej; Tomasz Ząbek; Anna Lewińska; Dominika Błoniarz; Iwona Rzeszutek; Maciej Wnuk

doi:10.1016/j.jbo.2022.100448

RNA 5-methylcytosine status is associated with DNMT2/TRDMT1 nuclear localization in osteosarcoma cell lines

J Bone Oncol. 2022 Jul 30:36:100448. doi: 10.1016/j.jbo.2022.100448. eCollection 2022 Oct.

Authors

Gabriela Betlej¹, Tomasz Ząbek², Anna Lewińska³, Dominika Błoniarz³, Iwona Rzeszutek³, Maciej Wnuk³

Affiliations

¹ Institute of Physical Culture Studies, College of Medical Sciences, University of Rzeszow, Rzeszow 35-310, Poland.
² Laboratory of Genomics, National Research Institute of Animal Production, Krakowska 1, Balice 32-083, Poland.
³ Department of Biotechnology, Institute of Biology and Biotechnology, College of Nature Sciences, University of Rzeszow, Pigonia 1, Rzeszow 35-310, Poland.

Abstract

Osteosarcoma (OS) is a pediatric malignant bone tumor with unsatisfying improvements in survival rates due to limited understanding of OS biology and potentially druggable targets. The present study aims to better characterize osteosarcoma U-2 OS, SaOS-2, and MG-63 cell lines that are commonly used as in vitro models of OS. We focused on evaluating the differences in cell death pathways, redox equilibrium, the activity of proliferation-related signaling pathways, DNA damage response, telomere maintenance, DNMT2/TRDMT1-based responses and RNA 5-methylcytosine status. SaOS-2 cells were characterized by higher levels of superoxide and nitric oxide that promoted AKT and ERK1/2 activation thus modulating cell death pathways. OS cell lines also differed in the levels and localization of DNA repair regulator DNMT2/TRDMT1. SaOS-2 cells possessed the lowest levels of total, cytoplasmic and nuclear DNMT2/TRDMT1, whereas in MG-63 cells, the highest levels of nuclear DNMT2/TRDMT1 were associated with the most pronounced status of RNA 5-methylcytosine. In silico analysis revealed potential phosphorylation sites at DNMT2/TRDMT1 that may be related to the regulation of DNMT2/TRDMT1 localization. We postulate that redox homeostasis, proliferation-related pathways and DNMT2/TRDMT1-based effects can be modulated as a part of anti-osteosarcoma strategy reflecting diverse phenotypic features of OS cells.

Keywords: DNA damage response; Osteosarcoma; RNA 5-methylcytosine; Redox homeostasis; TRDMT1; Telomere maintenance.